Vibration damping support



Dec 22, 9 I n. MARTIN 05,790

VIBRATION DAMPING SUPPORT Filed Feb. 10, 1941 Patented Dec. 22 1942 nirsp STATES PATENT OFFIC I 2,305,790;

VIBRATION nAMrmo sort-oar Hans Martim-Erfurt, Germany; vested in the Alien Property Custodian Application February 10,1941, Serial N6. 373,305

I, In Germany November 29,1939

3 Claims (01148-84),-

This invention; relates to vibration damping supports. for smallmachines, particularly office machines, of theenclosedtype in which the outer casing is; secured to the metal supporting base of the machine but does not itself support any of the machine parts.

The casing muflles the noise of operation of the machine parts but both the casing and table top or other support for the machine have relatively large surfaces that may radiate sound waves of greater magnitude than those directly established by the machine parts. The casings of metal or molded plastics are of light weight, as they do not support any of the mechanism, and relatively small impressed forces may result in high amplitude vibrations of a part or all of the casing at frequencies of mechanical resonance of the casing. These resonance effects, when present, may convert the casing or the supporting surface into sound amplifiers that more than offset the noise-suppressing action of the casing.

An object of the present invention is to provide novel vibration damping supports, for small enclosed machines, in the form of bodies of resilient material with a main section to be positioned between the machine base and a supporting surface, and an extension that projects beyond the edge of the base to engage the casing and the supporting surface. Another object is to provide supports of the type stated for use with machines in which the casing is secured to but spaced from the machine base, the supports having resilient ribs that project upwardly to fit betweensthe base and the casing. A further object is to provide supports for machines with flanged bases, thesupports including a relatively thick main section--with angularly arranged portions that terminate in surfaces for engagement with the flange of the base, and a section of lesser thickness that extends beyond the base flange to engage the casing.

These and other objects and advantages of the invention will be apparent from the following specification when taken with the accompanying drawing in which:

Fig. l is a fragmentary vertical sectionptaken on line'i-l of Fig. 2, of a support embodying the invention and the associated parts of a machine base and easing;

Fig. 2 is a fragmentary sectional view of the construction as seen from above the plane indicated by line 2--2 of Fig. 1

In the drawing, the reference numeral I identifies the caster pressed metal base of the machine, the base terminating along its edges in downwardly extending flanges"2.- The casing 3 has the general form of an inverted box that is telescoped over the base and is of slightly larger dimensions than the base. When the easing is formed of a'moldedplastic material, the

lower edges of sidewalls are reinforced at spaced points by inwardly projecting extensions 4 of the molded material, and conical openings ex-' tend through the reinforced sections to receive the rubber sleeves 5 and conical studs 6 that secure the casing to the base. The studs 6 have radial shoulders for engagement with the flange 2 when the studs are screwed into threaded openings in the flange, and the compression of the rubber sleeves is thereby limited to values that afford adequate support for the casing but that do not facilitate the transmission of mechanical vibrations from the base to the casing. The construction so far described is typic of the machines with which the vibration damping supports are to be used. The supports are preferably attached to the base to serve. as the feet of the machine but they may be separate from the machine and loosely seated in cups secured to the machine base or to the surface on which the machine is to be placed.

The support is formed of rubber or other elastic material and includes a relatively thick main section 8 with an upper suriace of substantial area for engagement with the lower face of the metal base I, and a section 9 of less thickness that extends beyond the base flange 2 to lie between the casing 3 and the supporting surface. A bore extends vertically through the main section 8 to receive the attaching stud i0, and a rigid sleeve ll is inserted in the bore to limit the compression of the resilient material by the stud In.

In the usual case of a rectangular machine base, the supports are arranged at the corners of the base and the main section 8 is of angular cross-section, as viewed in plan, with the projecting parts terminating in surfaces that en gage the flanges 2 to prevent inadvertent move-- ment of the support about the stud 10. A resilient rib l2 extends upwardly from the section 9 to fit snugly between the flanges 2 of the base and the casing walls. The upper edge of the rib I2 is beveled to facilitate the introduction of the rib into the gap. and depressions ii are formed in the outer face of the rib to fit about the reinforcements 4 of the casing. Resilient inserts ll of soft felt or the like extend between the ribs 12 of adjacent supports to close the gap between the machine base and the casings. The strips may be glued either to the casing or the base, but they do not form a connection between the parts and serve only to close the gaps.

The lower face of the support may be corrugated to preclude slipping upon a smooth surface and, as*j;sho wn,' it'maybe indented to formapentral recess l5 beneath the inner portiori'of the extension 9.

The main section 8 of a supporttransmits-the vv weight of the machine to a table .top or other vibration of the base andthe transmission-ct vibrations to the supporting surface. The lateral. extension 9 of the support .rloes not carry appreciable part of the weightof the machine but: 1 contacts both the casing and the supporting 'sur-' face, and thereby clamps any vibrations-of these members that may be transmitted to thern from the machine base,

The shapeof the resilient supportsTitian}v be parting from. the spirit of my invention as se forth in the following claims.

I claim:

1. A support of resilient materialfor machines havinga metalbasecarryingthemachineparts. and a casing secured to said base and cooperating therewith to form the housing of themachine; saidsupport a relatively thick main section iforlocatlii betweenthe machine base and a supporting surface, and a second sectlon of less thickness extending from the main I g v'section to lie between and engage the casing and supporting surface and, being resilient,"'da'mps the t s ot said asing and to prevent the supporting surface thereby to damp vflara- :of sound vibrations between said casing and said r lpporting surface.

' ;2.*As'u rt'asclaimed in claim 1, wherein a rib. projects upwardly from the second section l to -liev-between and engage the base and tho i n l 3. A support as claimed inclaim 1, wherein the j main section has m. jm i s in w syfor engalement' with a downwardly projectin n the 'base. 

